Electrode catheters have been in common use in medical practice for many years. They have been used to stimulate and map electrical activity in the heart and to ablate sites of aberrant electrical activity. More recently, therapeutic and diagnostic agents have been delivered into the heart, including the heart wall, also through a percutaneous transluminal approach with the use of injection catheters. In particular, catheters with a needle have been used for injection directly into the myocardium for a variety of treatments, including myocardial revascularization. For example, U.S. Pat. No. 6,309,370 entitled Intracardiac Drug Delivery, the entire disclosure of which is hereby incorporated by reference, is directed methods and apparatuses to provide accurate minimally-invasive methods and apparatus for intracardiac administration of drugs to the myocardium.
In use, the electrode catheter is inserted into a major vein or artery, e.g., femoral artery, and then guided into the chamber of the heart of concern. Under conventional procedures, navigation of the catheter to the target site is accomplished by a physician operating a deflection control handle aided by fluoroscopy of the heart region. And, while the physician manually controls and maintains the position of the catheter at the tissue target site, another staff member is needed to operate a separate needle control handle for injecting the needle into tissue and delivering therapeutic agent through the lumen of the injection needle. Such needle control handles are described in U.S. Pat. No. 6,575,931 (Ponzi) and U.S. Pat. No. 6,623,474 (Ponzi). In these needle control handles, a cylinder and piston arrangement is provided to extend the needle past the catheter distal tip to penetrate tissue and a syringe is provided to deliver the therapeutic agents. While such needle control handles are very effective, the consistency and accuracy of needle penetration and injection can be as varied as the visual and manual acuity of the different physicians or assistants operating the needle control handle. Indeed, people have different hand strengths and each person calibrates differently, not to mention the differences even with the very same person from one instance to the next. Thus, the consistency and accuracy in the use of needle control handles for tissue penetration and delivery of therapeutic agents, particularly in terms of injection volume and injection rate, can be improved upon.
Moreover, in recent years, remote (remote magnetic technology (RMT)) and robotic manipulation of catheters have been used for mapping and other procedures. These remotely guided catheters allow for more automation with improved accuracy and efficiency in the maneuvering and positioning of catheters reducing the dependence of success based upon the physical dexterity and physician manipulation manual skill. And, by enabling navigation from a location remote from patient, these catheters have also greatly reduced, if not eliminated, the physician's exposure to fluoroscopic radiation. However, while remote catheters obviate the use of manual deflection control handles, the needle control handle has continued under conventional design to be tethered to the proximal end of the catheter body and thus still near the patient. Thus, it would be desirable that the needle control handle be automated to obviate the need for a needle control assistant to control needle extension, injection and retraction.
Accordingly, it is desirable to provide device and system for automating needle control, including the extension and retraction of the needle and the actuation of the syringe for greater consistency and accuracy in use, including needle penetration, injection volume and injection rate. It is also desirable for the device and system to allow the use of larger syringes so that a single syringe can provide the volume of therapeutic agents called for in current clinical procedures. It is further desirable for the device and system to provide agitation of the therapeutic agents carried in the syringe to minimize settling and coagulation. It is yet further desirable for the device and system to detect occlusion or other possible malfunctions so that actuation of the syringe does not occur until tissue penetration has been achieved, and actuation of the syringe is interrupted if an occlusion is detected.